TW202112945A - Pre-dried polystyrene/alumina compound for foam extrusion - Google Patents

Abstract

A polystyrene (PS) composition for making an extruded foam, the PS composition comprising: a dried PS/alumina compound comprising a PS and an alumina additive, wherein the dried PS/alumina compound has a moisture content, measured by Coulometer, that is less than or equal to about 0.05 weight percent (wt%); and a blowing agent.

Description

Pre-dried polystyrene/alumina mixture for foam extrusion

This disclosure is about the manufacture of polystyrene (PS) foam. More particularly, the present disclosure provides PS compositions and methods for increasing the solubility of foaming agents during PS foam extrusion. More particularly, the present disclosure provides PS compositions and methods for producing PS foams with required insulating properties, and the PS foams produced. [Cross-reference of related applications]

This application claims the benefits of U.S. Provisional Patent Application No. 62/884,289 filed on August 8, 2019, the entirety of which is intended to be incorporated herein by reference. [Statement regarding federally sponsored research or development]

None applicable. [Quotation of Microfilm Attachment]

None applicable.

Polystyrene can be foamed and formed into various objects, such as foamed rods, slats, and sheets, which are well known in this technology. Polystyrene (PS) foams formed by using hydrofluorocarbon (HFC) foaming agents such as HFC 134a can be used to construct insulating boards. For superior insulation properties (e.g. as measured by the R value), a high HFC blowing agent concentration in the foam board is required. Commonly used physical blowing agents (such as hydrofluorochlorocarbons (HCFC), hydrofluorocarbons (HFC), or their combinations) can cause smog formation and have high ozone depletion potential or global warming potential ( GWP), and/or can be a harmful air pollutant. For example, due to its high GWP (Global Warming Potential), some HFCs including HFC 134a will be banned by 2021. Therefore, there is a need for alternatives to HFC (such as HFC 134a). Hydrofluoroolefin (HFO) appears to be one of the candidates due to its zero GWP.

Despite advances in foam manufacturing, there is still a need for simple and economical means to obtain the solubility of the foaming agent (including both HFC and HFO) that is enhanced in the polystyrene composition used for foam extrusion and / Or strengthen the retention of the blowing agent in the polystyrene foam.

Disclosed here is a polystyrene (PS) composition for making extruded foams. The PS composition includes: a dry PS/alumina mixture containing PS and alumina additives, wherein the dry The PS/alumina mixture has a water content of less than or equal to about 0.05 weight percent (wt%) measured by a coulometer; and a foaming agent. Also disclosed here is a low-density polystyrene (PS) foam manufactured by extruding the PS composition, wherein the low-density PS foam does not contain the dry PS/alumina than through extrusion. Other similar low-density PS foams made from the mixed PS composition contain higher foaming agent concentration. Further disclosed here is a low-density polystyrene (PS) foam manufactured by extruding the PS composition, wherein the low-density PS foam is relatively extruded without the dry PS/ Other similar low-density PS foams made from the PS composition of the alumina mixture exhibit at least one superior insulating property. Also disclosed here is a low-density polystyrene (PS) foam manufactured by extruding the PS composition, wherein the low-density PS foam exhibits at least one mechanical property, which is at least equivalent to The mechanical properties of other similar low-density PS foams produced by extruding the PS composition without the dry PS/alumina mixture. Further disclosed herein is a low density polystyrene (PS) foam manufactured by extruding the PS composition, wherein the blowing agent contains one or more hydrofluoroolefins (HFO), and wherein the low density The PS foam exhibits at least one insulating property that is at least equal to the PS/alumina mixture that does not contain the dry PS/alumina mixture through extrusion and contains one or more selected from the group consisting of hydrofluorocarbons (HFC) The insulating properties of other similar low-density PS foams made by the PS composition of the foaming agent.

Also disclosed here is a method of manufacturing low-density polystyrene (PS) foam. The method comprises: forming a polystyrene (PS)/alumina mixture containing PS and alumina additives; from the PS/ The alumina mixture removes moisture to form a dry PS/alumina mixture, wherein the dry PS/alumina mixture has a value of less than or equal to about 0.05 weight percent (wt%) measured by a coulometer The water content; blending the dry PS/alumina mixture, blowing agent, and optionally one or more additional additives to form a foamable mixture; and by extruding the foamable mixture through a mold And enter the low pressure zone to produce foam. It also provides a low-density polystyrene (PS) foam manufactured by the method. In a specific example, the low-density PS foam has a higher content than other similar low-density PS foams produced by extruding a foamable mixture that does not contain the dry PS/alumina mixture. The blowing agent concentration and/or exhibit at least one superior insulation or mechanical property.

Also disclosed here is a dry polystyrene (PS)/alumina mixture for making extruded foams. The dry PS/alumina mixture contains an extruded mixture of PS and alumina additives. Wherein the extruded mixture has been dried to provide the dry PS/alumina mixture, so that the dry PS/alumina mixture has less than or equal to about 0.05 weight percent (wt%) measured by a coulometer The dry PS/alumina mixture contains from about 0.01 to about 20.0 weight percent (wt%) of alumina additive.

It should be understood at the outset that although illustrative implementations of one or more specific examples are provided below, the disclosed compositions, methods, and/or products can be implemented using any number of techniques, whether they are currently known or existing . The disclosure should never be limited to the illustrative implementation, the drawings, and the techniques described below, including the exemplified design and implementation illustrated and described here, but may be within the scope of the attached patent application together with the full scope of equivalents. The inside is improved. This disclosure describes a dry polystyrene (PS)/alumina mixture, which is used in a polystyrene (PS) composition containing the dry PS/alumina mixture and a blowing agent. Surprising discovery: the use of the dry PS/alumina mixture and the PS composition containing it enables PS to retain a greater concentration of foaming agent in the finished PS foam, improving the solubility of physical foaming agents such as but not Limited to the solubility of HFC (hydrofluorocarbon), HFO (hydrofluoroolefin), carbon dioxide (CO ₂ ) in polystyrene during foam extrusion, and/or increase the foaming agent in the resulting PS foam Retention in the bubble body. In particular, the PS composition includes a dry PS/alumina mixture, which includes PS (such as polystyrene crystals) and alumina additives, wherein the dry PS/alumina mixture has a value measured by a coulometer A water content less than or equal to about 0.1, 0.05, 0.04, 0.03, 0.02, 0.01, or 0 weight percent (wt%); and a foaming agent.

In specific examples, the PS composition of the present disclosure has a wider foam extrusion processing window, as indicated by the foamability at a higher foaming agent concentration and/or a wider temperature range. In a specific example, the PS foam (such as low-density PS foam) obtained by extruding/blowing the PS composition disclosed herein has a higher foaming agent (such as HFC or HFO) concentration (such as Due to the high foaming agent solubility required during foam extrusion), increased foaming agent retention in the resulting PS foam, and/or enhanced foam mechanical properties (such as superior insulation properties) ). The potential advantage of the PS composition of the present disclosure is that the composition can enable the polystyrene insulation board manufacturer to replace the commonly used HFC 134 with a low GWP (Global Warming Potential) blowing agent such as HFO.

In a specific example, the use of a dry PS/alumina mixture to form the PS composition of the present disclosure will be in the PS composition (and therefore in the resulting PS foam) during foam extrusion. The solubility of the blowing agent is increased by at least 10, 20 or 30%. The alumina additive can be present in the dry PS/alumina mixture in the range from about 0.01 to about 20.0 weight percent (wt%) in specific examples. In a specific example, the solubility of the blowing agent in the PS composition is higher than or equal to about 6.5, 7, 7.5, or 8 weight percent.

Regarding the use of HFO as a blowing agent, there are two main challenges. Firstly, HFO is a very expensive refrigerant/foam blowing agent. Secondly, compared with common blowing agents (such as HFC 134a), HFO has relatively low solubility in polystyrene and is therefore difficult to The desired insulation properties are obtained in the resulting foam product. In addition, when physical blowing agents such as carbon dioxide are used, polystyrene generally does not exhibit good foaming behavior. In particular, when used as a physical foaming agent in a traditional polystyrene foaming process, carbon dioxide produces non-descript masses of polymer materials or poor quality thermoplastic foams that tend to collapse. Without being limited to theory, this may be the result of the lack of polymer-gas compatibility and the limited solubility of carbon dioxide in the molten thermoplastic extrudate, resulting in the foam structure, as the thermoplastic / The combination of foaming agents leaves the mold, creating highly open vesicles that are out of control. In addition, even if the resultant foam has a visible foam structure, the foam easily collapses quickly due to the relatively high permeability of carbon dioxide with respect to air (that is, because the carbon dioxide is rapidly removed from the vesicles) Part of the vacuum caused by escaping allows the vesicle to collapse), and within a few hours of being manufactured, it becomes unsuitable for most practical applications. Through this disclosure, in some low-density PS foam applications, non-HFC-based blowing agents such as HFO and CO ₂ can be used as blowing agents or auxiliary blowing agents. In a specific example, the dry PS/alumina mixture containing the PS composition of the present disclosure can be transformed into a non-flammable, inexpensive and low GWP (Global Warming Potential) foaming agent such as CO ₂ , which is There is enhanced solubility of the blowing agent during extrusion and/or retention of the enhanced blowing agent in the manufactured foam.

This disclosure describes a dry polystyrene (PS)/alumina mixture for a polystyrene (PS) composition containing the dry PS/alumina mixture and a blowing agent. Surprisingly, it was found that the use of the dry PS/alumina mixture and the PS composition containing them enables the PS to maintain a greater concentration of the foaming agent in the PS foam finished product, and to improve the foaming agent extrusion During the period, physical blowing agent (such as but not limited to, HFC (hydrofluorocarbon), HFO (hydrofluoroolefin) and carbon dioxide (CO ₂ ) solubility in polystyrene, and/or the blowing agent in the obtained PS Retention in the foam. In particular, the PS composition includes a dry PS/alumina mixture, which contains PS (such as polystyrene crystals) and alumina additives, wherein the dry PS/alumina mixture has a The water content measured by the electricity meter is less than or equal to about 0.05 weight percent (wt%); and the foaming agent.

In specific examples, the PS composition of the present disclosure has a wider foaming extrusion processing window, as indicated by the foamability at a higher foaming agent concentration and/or a wider temperature range. In a specific example, the PS foam (such as low-density PS foam) obtained by extruding/foaming the PS composition disclosed herein has a higher foaming agent (such as HFC or HFO) concentration (such as due to High foaming agent solubility required during foam extrusion), increased foaming agent retention in the resulting PS foam, and/or enhanced foam mechanical properties (such as superior insulation properties). The potential advantage of the PS composition of the present disclosure is that the composition enables the polystyrene insulation board manufacturer to replace the commonly used HFC 134 with a low GWP (Global Warming Potential) foaming agent such as HFO.

In a specific example, a dry PS/alumina mixture is used to form the PS composition of the present disclosure. During the extrusion of the foam, the PS composition (and therefore in the resulting PS foam) ) The solubility of the blowing agent is increased by at least 10, 20 or 30%. The alumina additive can be present in the dry PS/alumina mixture in the range from about 0.01 to about 20.0 weight percent (wt%) in specific examples.

There are two main challenges in using HFO as a blowing agent. Firstly, HFO is a very expensive refrigerant/foam blowing agent. Secondly, HFO in polystyrene can have relatively low solubility compared with common blowing agents (such as HFC 134a), and therefore it is difficult to The desired insulation properties are obtained in the resulting foam product. In addition, when physical blowing agents such as carbon dioxide are used, polystyrene generally does not exhibit good foaming behavior. In particular, when used as a physical foaming agent in a traditional polystyrene foaming process, carbon dioxide produces non-descript quality polymeric materials or poor quality thermoplastic foams that tend to collapse. Without being limited to theory, this may be the result of the lack of polymer-gas compatibility and the limited solubility of carbon dioxide in the molten thermoplastic extrudate, resulting in the foam structure, as the thermoplastic / The combination of foaming agents leaves the mold, creating highly open vesicles that are out of control. In addition, even if the resultant foam has a visible foam structure, the foam easily collapses quickly due to the relatively high permeability of carbon dioxide with respect to air (that is, because the carbon dioxide is rapidly removed from the vesicles) Part of the vacuum caused by escaping allows the vesicle to collapse), and within a few hours of being manufactured, it becomes unsuitable for most practical applications. According to this disclosure, in some low-density PS foam applications, non-HFC foaming agents such as HFO and CO ₂ can be used as foaming agents or auxiliary foaming agents. In a specific example, the dry PS/alumina mixture containing the PS composition of the present disclosure can be transformed into a non-flammable, inexpensive and low GWP (Global Warming Potential) foaming agent such as CO ₂ , which is There is enhanced solubility of the blowing agent during extrusion and/or retention of the enhanced blowing agent in the manufactured foam.

Although it is believed that the following terms are fully understood by those skilled in the art, the following definitions are presented to facilitate the description of the subject matter currently disclosed. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the subject currently disclosed belongs.

Styrene, also known as vinyl benzene, is an aromatic compound that is mass-produced from ethylbenzene. The most common styrene production method involves the dehydrogenation of ethylbenzene, which produces the crude product of styrene monomer and unreacted ethylbenzene and hydrogen. Polystyrene is an aromatic polymer made from styrene monomer. Polystyrene is a widely used polymer found in insulation, packaging, and disposable tableware, as well as foamed products, including foamed cups.

Different types of polystyrene materials can include general-purpose polystyrene (GPPS) and high-impact polystyrene (HIPS). Many conditions affect the properties of the resulting product, including processing time, temperature, pressure, purity of monomer raw materials, and the presence of additives or other compounds. These and other processing conditions change the physical and chemical properties of the polystyrene product, affecting its suitability for the desired use.

Foamed polystyrene has the advantages of low cost, light weight and high structural strength for its density. General polystyrene foam also has relatively high impact resistance and has excellent electrical and thermal insulation properties. Foamed polystyrene is used in a variety of applications such as insulation, packaging, coolants, food packaging, decorative objects, and cushioning materials for protecting and securing goods during transportation. In addition, polystyrene foams are generally classified into three general areas: low density, medium density and high density. Low-density polystyrene foam often has a density from about 1 to about 3 lb/ft ³ , but medium-density foam can have a ^{density range from about 4 to about 19 lb/ft 3} , and high-density foam body often have from about 20 to 30 lb / ft ³ density of the range.

The two main types of polystyrene foam are extruded polystyrene (XPS) foam and expanded polystyrene (EPS) foam. The extruded polystyrene foam is generally formed by mixing polystyrene with additives and blowing agent and entering an extruder that heats the mixture. The mixture is then extruded, foamed into the desired shape, and cooled. Expanded polystyrene foam is generally formed by using steam or hot air to expand solid polystyrene beads containing a blowing agent such as pentane. These pre-expanded beads can later be molded into the desired shape and expanded again with steam or hot air to fuse the beads together.

The term "foaming agent" as used herein refers to any of a variety of substances, which alone or in combination with at least one other substance can produce a vesicle-like structure in a plastic mass. Therefore, the term includes, but is not limited to, gas that expands when pressure is released, soluble solids that leave holes when exuded, liquid that develops vesicles when changed to gas, and/or decomposes or reacts under the influence of heat. Chemical agents that form gas.

In the manufacture of extruded polystyrene foams, blowing agents such as methyl chloride, ethyl chloride, chlorocarbons, fluorocarbons (including HFC) and chlorofluorocarbons (CFC) are generally used. However, due to potential environmental impacts (including ozone depletion or global warming), such blowing agents are strictly regulated. The continuing trend in the development of extrusion foaming processes is to find environmentally friendly chemicals as foaming agents. Some foaming processes have used hydrofluoroolefins (HFO) or carbon dioxide (CO ₂ ) as blowing agents or auxiliary blowing agents. For the required insulation properties, HFO is better due to its low thermal conductivity and minimal environmental impact. However, the solubility of HFO in polystyrene needs to be further improved, such as the one provided here, in order to comply with the stringent requirements of the regulations on the board of building insulation foam.

The term "thermoplastic foam" refers to a vesicle-like polymer in which many bubbles or vesicles are dispersed in a polymer matrix that can be repeatedly heated, melted, formed, and cooled. As a result, the thermoplastic foam can be easily melted and recycled. The polystyrene foam manufactured according to the present disclosure may be a thermoplastic foam.

Although most of the above definitions are basically understood by those skilled in the art, due to the special description of the disclosed subject matter here, one or more of the above definitions can be used in a way that is different from the meaning commonly understood by those skilled in the art. The above is defined.

What is disclosed here is a polystyrene (PS) composition used to make polystyrene foams (also referred to herein as "PS blends", "PS blends" or "foamable mixtures" ). The PS composition disclosed herein includes a dry PS/alumina mixture, which includes PS and alumina additives. The dry PS/alumina mixture has a water content of less than or equal to about 0.05 weight percent (wt%) measured by a coulometer. The dry PS/alumina mixture can be formed by forming a polystyrene (PS)/alumina mixture containing PS and alumina additives, and removing moisture from the PS/alumina mixture to form the dry PS /Alumina mixture, wherein the dry PS/alumina mixture has a water content of less than or equal to about 0.05 weight percent (wt%) measured by a coulometer. Optionally, the combination of the PS and the alumina additive produces the dry PS/alumina mixture, that is, the PS and the alumina additive are sufficiently dry so that the combination (without further removal of moisture) produces a power source The required water content measured by the meter is less than or equal to about 0.05 weight percent (wt%), so that the PS/alumina mixture is considered to be a dry PS/alumina mixture. As described in detail below, the PS composition of the present disclosure can further include a foaming agent (for example, one foaming agent or multiple foaming agents). Additional additives described below may be included in the PS composition (for example, incorporated into or combined with the dry PS/alumina mixture to form the polystyrene composition). For example, as described further below, such additional additives can include SRA, antioxidants, flame retardants, or combinations thereof.

The PS composition of the present disclosure includes polystyrene, which is incorporated into the PS composition through the dry PS/alumina mixture. A variety of polystyrene homopolymers and copolymers can be used, as well as high-impact polystyrene (HIPS) formed by polymerization or irradiation technology. In a specific example, the PS can include polystyrene crystals (also known as general polystyrene (GPPS)), high-impact polystyrene (HIPS), PS copolymer, or a combination thereof. In a specific example, the polystyrene copolymer may contain a metal monomer. For example, in a specific example, the metal monomer includes zinc dimethacrylate (ZDMA). Suitable polystyrene copolymers can include a variety of polymers such as, but not limited to, glycidyl methacrylate, 2-hydroxyethyl methacrylate copolymer, acrylonitrile, and the like. In specific examples, suitable polystyrene can be derived from petroleum-based sources and/or biomass-based sources.

In a specific example, the dry PS/alumina mixture and the polystyrene in the PS composition disclosed herein have a range from 0.2 to 30 grams (g)/10 minutes (min) as measured by D1238 , 1.0 to 20 g/10 min, or 1.0 to 10.0 g/10 min range of melt flow rate (MFR).

In a specific example, the dry PS/alumina mixture and PS composition of the present disclosure contain polystyrene crystals. The PS crystal can be characterized by measuring from 0.2 g/10 min to 30 g/10 min, from 1.0 g/10 min to 20 g/10 min, or from 1.0 g/10 min to 10.0 g according to ASTM D-1238 /10 min melt flow rate; measured according to ASTM D-638 from 6,000 psi to 8,000 psi (from 41.4 to 55.2 MPa), from 6,500 psi to 8,000 psi (from 44.8 to 55.2 MPa), or from 7,000 psi to 8,000 psi (from 48.3 to 55.2 MPa) tensile strength; from 400,000 psi to 480,000 psi (from 2.8 to 3.3 GPa), from 420,000 psi to 460,000 psi (from 2.9 to 3.2 GPa), as measured by ASTM D-638, or Tensile modulus from 430,000 psi to 450,000 psi (from 3.0 to 3.1 GPa); from 400,000 psi to 480,000 psi (from 2.8 to 3.3 MPa), from 420,000 psi to 460,000 psi (from 2.9 To 3.2 MPa), or from 430,000 psi to 450,000 psi (from 3.0 to 3.1 MPa) flexural modulus; from 10,000 psi to 15,000 psi (from 68.9 to 103.4 MPa), from 12,000 psi as measured by ASTM D-790 Flexural strength to 14,000 psi (from 82.7 to 96.5 MPa), or from 13,000 psi to 14,000 psi (from 89.6 to 96.5 MPa); from 190°F to 220°F (from 87.8°C to 104.4) as measured by ASTM D-648 ℃), from 200 ℉ to 220 ℉ (from 93.3 ℃ to 104.4 ℃), from 210 ℉ to 220 ℉ (from 98.9 ℃ to 104.4 ℃) annealing heat distortion; and/or from 200 ℉ as measured according to ASTM D-1525 ℉ to 230°F (from 93.3°C to 110.0°C), from 210°F to 230°F (from 98.9°C to 110.0°C), or from 215°F to 225°F (from 101.7°C to 107.2°C) Vicat softening .

In a specific example, the dry PS/alumina mixture and PS composition of the present disclosure includes HIPS. HIPS refers to any vinyl aromatic polymer reinforced with elastomers. The vinyl aromatic monomer may include, but is not limited to, styrene, α-methylstyrene, and ring-substituted styrene. HIPS may further include comonomers including methyl styrene; halogenated styrene; alkylated styrene; acrylonitrile; esters of (meth)acrylic acid with alcohols having 1 to 8 carbon atoms; N-vinyl Compounds such as vinylcarbazole and maleic anhydride; compounds containing two polymerizable double bonds such as divinylbenzene or butylene diacrylate; or combinations thereof. The comonomer can be present in an amount that effectively imparts one or more properties required by the user to the polystyrene resin. Such an effective amount can be determined by a person skilled in the art with the help of the present disclosure. For example, the amount of the comonomer present in the styrene polymer composition may be from 1 wt% to 99.9 wt%, and from 1 wt% to 90 wt% based on the total weight of the reaction mixture forming the polystyrene. , Or from 1 wt% to 50 wt%.

In the HIPS, the elastic material is generally embedded in the polystyrene matrix. Examples of elastic materials include conjugated diene monomers, which include, but are not limited to, 1,3-butadiene, 2-methyl-1,3-butadiene, 2-chloro-1,3-butadiene, 2-methyl-1,3-butadiene, or a combination thereof. In a specific example, the HIPS includes an aliphatic conjugated diene monomer as the elastomer. Without limitation, examples of suitable aliphatic conjugated diene monomers include C4 to C9 dienes, such as butadiene monomers. Blends or copolymers of the diene monomers can also be used. Likewise, a mixture or blend of one or more elastomers can be used to make the HIPS. In a specific example, the elastomer includes a homopolymer of diene monomer; in a specific example, the elastomer includes polybutadiene. The elastomer is present in the HIPS in an amount effective to produce one or more properties required by the user. Such an effective amount can be determined by a person skilled in the art with the help of the present disclosure. For example, the amount of the elastomer present in the HIPS may be from 1 wt% to 20 wt%, from 2 wt% to 15 wt%, or from 5 wt% to 11 wt% based on the total weight of the HIPS.

In a specific example, the HIPS used in the dry PS/alumina mixture or PS composition of the present disclosure has a measured value of from 1 g/10 min to 40 g/10 min and 1.5 g/10 min according to ASTM D-1238. Melt flow rate from g/10 min to 20 g/10min, or from 2 g/10 min to 15 g/10min; according to ASTM D-3029, from 5 in-lb to 200 in-lb (from 0.6 to 22.6 Nm), from 50 in-lb to 180 in-lb (from 5.6 to 20.3 Nm), or from 100 in-lb to 150 in-lb (from 11.3 to 16.9 Nm) falling dart impact; according to ASTM D-256 measured from 0.4 ft-lbs/in to 5 ft-lbs/in (from 0.4 to 267 J/m), from 1 ft-lbs/in to 4 ft-lbs/in (from 53 to 213 J/m), or Izod impact from 2 ft-lbs/in to 3.5 ft-lbs/in (from 107 to 187 J/m); from 2,000 psi to 10,000 as measured by ASTM D-638 psi (from 13.8 to 68.9 MPa), from 2,800 psi to 8,000 psi (from 19.3 to 55.1 MPa), or from 3,000 psi to 5,000 psi (from 20.7 to 34.5 MPa) tensile strength; measured according to ASTM D-638 Tensile modulus from 100,000 psi to 400,000 psi (from 0.7 to 2.7 GPa), from 200,000 psi to 400,000 psi (from 1.4 to 2.7 GPa), or from 250,000 psi to 380,000 psi (from 1.7 to 2.6 GPa); according to ASTM Elongation from 0.5% to 90%, from 5% to 70%, or from 35% to 60% as measured by D-638; from 3,000 psi to 15,000 psi (from 20.7 to 103.4) as measured by ASTM D-790 MPa), flexural strength from 4,000 psi to 10,000 psi (from 27.6 to 68.9 MPa), or from 6,000 psi to 9,000 psi (from 41.4 to 62.1 MPa); from 200,000 psi to 450,000 psi as measured by ASTM D-790 (From 1.4 to 3.1 GPa), from 230,000 psi to 400,000 psi (from 1.6 to 2.8 GPa), or from 250,000 psi to 3 Flexural modulus of 50,000 psi (from 1.7 to 2.4 GPa); from 180°F to 215°F (from 82°C to 102°C), from 185°F to 210°F (from 85°C to 99 ℃), annealing heat deformation from 190°F to 205°F (from 88°C to 96°C); from 195°F to 225°F (from 91°C to 107°C), from 195°F to 220 according to ASTM D-1525 ℉ (from 91°C to 104°C), or from 200°F to 215°F (from 93°C to 102°C) Vicat softening; and/or from 30 to 100, from 30 to 100, as measured by ASTM D-523 40 to 98, or 60∘ gloss from 50 to 95.

The dry PS/alumina mixture and PS composition of the present disclosure contain alumina additives. Any suitable alumina known to the skilled person can be used as the alumina additive. In specific examples, the alumina additive comprises from about 64 to about 80, from about 72 to about 76, from about 72 to about 74, or greater than or equal to about 70, 72, or 74 wt% alumina (Al ₂ O ₃ ). In a specific example, the alumina additive contains less than or equal to about 0.002 wt% sodium oxide (Na ₂ O). In a specific example, the rest of the alumina composition (that is, the rest contains components other than alumina or sodium oxide) includes titanium oxide (TiO ₂ ), silicon _{oxide (SiO 2} ), and iron oxide (such as oxide Iron (III), Fe ₂ O ₃ ). In specific examples, the alumina additive has a range of from about 5 to about 60, from about 26 to about 60, from about 35 to about 60, or greater than or equal to about 5, 10, 20, 30, 40, 50 , Or 60μm d ₅₀ particle size (or mass median diameter), which is defined as 50% of the sample plastids smaller than this diameter. In a specific example, the alumina additive has a range of from about 80 to about 360 m ² /g, from about 35 to about 400 m ² /g, and from about 150 to about 150 m 2 /g as measured by Buot (BET) technology. 360 m ² / g, from / g range from about 200 to about 360 m ² of, or greater than or equal to about 35,80,100,150 or 230 m ² / g surface area. In a specific example, the alumina additive has a pore volume in the range from about 0.3 to about 1.5 mL/g, from about 0.5 to about 1.3 mL/g, or from about 0.5 to about 1.0 mL/g. In a specific example, the alumina additive has a range of from about 4 to about 50 nm, from about 4.5 to about 20 nm, or from about 5.5 to about 5.5 as measured by x-ray diffraction at the (120) diffraction peak. About 120 crystallite size in the 10 nm range. In a specific example, the alumina additive includes CATAPAL® obtained from Sasol, PURAL® obtained from Sasol, or a combination thereof. For example, in a specific example, the alumina additive includes CATAPAL® A, CATAPAL® B, CATAPAL® Cl, CATAPAL® D, CATAPAL® 200, PURAL® SB, PURAL® SCF, PURAL® 200, PURAL® BT, or its combination. Table 1 shows exemplary alumina additives that can be utilized in the PS/alumina mixture of the present disclosure (eg, the PS/alumina mixture in which moisture is removed to form the dry PS/alumina mixture). This list is not exhaustive, and with the help of this disclosure, any suitable alumina additives described herein or known to those skilled in the art can be utilized in specific examples. Without wishing to be bound by theory, the alumina additive can be used as an infrared (IR) attenuator in a specific example.

Table 1: Alumina additives in PS/alumina mixtures suitable for the present disclosure General physical/chemical properties CATAPAL® A CATAPAL® B PURAL® SB PURAL® SCF CATAPAL® C1 CATAPAL® D PURAL® 200 & CATAPAL® 200 PURAL® BT Al ₂ O ₃ (%) 72 72 74 74 72 76 80 64 Na ₂ O (%) 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 Relaxed population Density (g/L) 670-750 670-750 600-850 500-700 670-750 700-800 500-700 500-700 Fill population Density (g/L) 800-1100 800-1100 800-1100 800-1100 800-1100 800-1100 700-900 600-800 Particle size, d ₅₀ (µm) 60 60 45 25 60 40 40 5-10 BET surface area** (m ² /g) 250 250 250 250 230 220 100 360 Pore volume *** (mL/g) 0.45 0.50 0.50 0.50 0.50 0.55 0.77 0.30 Crystallite size, 120 (nm) <4.5 4.5 5.0 5.0 5.5 7.0 40 40 ** Specific surface area measured by Bouart’s theory *** The ratio of the air volume of the porous material to the total weight of the porous material

In a specific example, the dry PS/alumina mixture contains from about 0.01 to about 20.0 weight percent (wt%), from about 0.1 to about 10 wt%, from about 0.2 to about 1 wt%, less than or equal to About 10, 7, or 5 wt%, or higher than or equal to about 0.1, 0.2, or 0.5 wt% of the alumina additive.

As indicated above, the PS composition of the present disclosure can further include one or more additional additives. In a specific example, the PS composition (for example, the PS/alumina mixture whose moisture is removed to form the dry PS/alumina mixture, and the dry PS/alumina mixture that is utilized to form the PS composition) The aluminum compound, and/or the PS composition) contains one or more low solubility and/or retention additives or "SRA", as described in U.S. Patent Application No. 16/014,883. The disclosure content as a whole is incorporated here for the purpose of not opposing the disclosure content. In specific examples, the SRA can include epoxidized soybean oil (ESO), epoxidized polybutadiene, mineral oil (MO), glyceryl monostearate (GMS), glyceryl tristearate (GTS), IRGANOX 1010 ^® (tetrakis (3-(3,5-di-tert-butyl-4-hydroxyphenyl) pentaerythritol propionate), or a combination thereof. Without wishing to be bound by theory, it is assumed that the SRA Existence can further increase the solubility of the blowing agent, thereby improving the compatibility in PS (for example, melted PS, such as during extrusion), and increasing the mobility of the polymer chain due to the plasticizing effect. The presence of SRA can reduce the activation energy for foam nucleation or vesicle growth. This can lead to the production of a large number of vesicles in specific cases, thereby reducing the density of the foam.

In a specific example, the PS composition can comprise from about 0.01 to 10.0 weight percent (wt%), from about 0.01 to 5.0 wt%, from about 0.01 to 2.0 wt%, from about 0.1 to 1.0 wt%, or from about 0.01 To 0.50 wt% of the SRA, the weight percentage is based on the total weight of the PS composition. In a specific example, the dry PS/alumina composition includes about 0.01, 0.05, 0.1, 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75, based on the total weight of the dry PS/alumina composition. 2.0, 2.25, 2.5, 2.75, 3.0, 3.25, 3.5, 3.75, 4.0, 4.25, 4.5, 4.75, or 5.0 wt% of the SRA.

In a specific example, the dry PS/alumina mixture and/or PS composition of the present disclosure contains low-concentration mineral oil (MO) and/or epoxidized soybean oil (ESO) as SRA. Without wishing to be bound by theory, it is assumed that MO and ESO can plasticize the PS melt to some extent, and effectively improve the "free volume" by increasing the mobility of the polymer chain segments. The polar substance of the ESO can promote the diffusion of polar blowing agent molecules throughout the PS melt. Therefore, in a specific example, adding ESO to PS to manufacture the PS composition of the present disclosure can enable PS to be foamed at a relatively low temperature with a high foaming agent concentration. Because the presence of MO and/or ESO may adversely affect the mechanical properties of the foam, such as the melt strength of polystyrene (if this effect is obvious, it can cause the vesicle to collapse undesirably), so the PS containing this SRA The composition can be fine-tuned to obtain the most ideal balance between the improvement of foaming agent solubility and melt strength. For example, in a specific example, a strengthening agent (such as, but not limited to, high-rigidity poly(phenylene oxide) (PPO), poly-αmethylstyrene, or a combination thereof) may be added to the PS composition (for example, incorporated in the PS/alumina mixture, combined with the dry PS/alumina mixture, and/or combined with the dry PS/alumina mixture to form the PS composition) to obtain the desired foam Compressive strength.

Although epoxidized soybean oil is cited in the specific examples for description, the SRA of the present disclosure may include any of a wide variety of epoxidized fatty acids and esters. For example, in specific examples, the epoxidized fatty acid can include: myristic acid, myristic acid, palmitic acid, palmitoleic acid, heptadecanoic acid, heptadecoleic acid, stearic acid, oleic acid, linoleic acid, Linolenic acid, arachidic acid, codoleic acid, eicosadienoic acid, behenic acid, erucic acid, lignoceric acid, or a combination thereof. This fatty acid can be found in a variety of vegetable oils, including but not limited to linseed oil, tung oil, safflower oil, soybean oil, castor oil, cottonseed oil, peanut oil, rapeseed oil, coconut oil, palm oil, olive oil, corn oil , Corn germ oil, sesame oil, peach seed oil, peanut oil, soybean lecithin, and egg yolk lecithin. Therefore, a variety of epoxidized fatty acids can be used in the PS composition according to the present disclosure. In specific examples, the SRA contains acrylated epoxidized fatty acids, such as those described in US Patent No. 8,648,122, the disclosure of which is incorporated herein in its entirety for the purpose of not objecting to the disclosure.

In a specific example, the SRA contains mineral oil (MO). As used herein, MO can be any light mixture of alkanes from mineral sources, such as petroleum distillates, and includes mineral oil mixtures from different sources or methods. The MO may be a liquid by-product of crude oil refining, for example.

In a specific example, the SRA contains epoxidized polybutadiene. The epoxidized polybutadiene contains epoxy groups (or "oxyethylene oxide" groups) on the polymer backbone. In a specific example, the epoxidized polybutadiene can contain from about 0.01% to about 5.0%, from about 0.01% to about 2.0%, from about 0.01% to about 1.0% of ethylene oxide oxygen. In a specific example, the epoxidized polybutadiene can have a range of from about 0.1 to about 5.0 meq/g, from about 0.5 to about 3.0 meq/g, or from about 1.0 to about 2.0 as measured by ASTM D1652. Epoxy value in the meq/g range. In a specific example, the molecular weight of epoxidized polybutadiene ranges from 800 to 10,000.

In a specific example, the SRA contains glyceryl monostearate (GMS). In a specific example, the PS composition of the present disclosure includes glyceryl tristearate (GTS), which is bulkier than GMS, and in a specific example, it can particularly impart beneficial properties to the PS foam.

In a specific example, the SRA further improves the solubility of the foaming agent in the PS used for foam extrusion. In a specific example, the solubility of the foaming agent in the foamable mixture of the SRA is at least 5, 7, 10 or 20% higher than the solubility of the foaming agent in the foamable mixture without the additive .

Without wishing to be bound by theory, the SRA can act as a permeation barrier in the resulting polystyrene foam of the present disclosure, thereby reducing the permeation rate of the blowing agent through the cell wall of the PS foam.

In a specific example, the PS in the PS composition of the present disclosure further includes one or more additional additives utilized to impart desired physical properties such as increased gloss or color. Examples of such additives include, but are not limited to, stabilizers, talc, antioxidants, UV stabilizers, lubricants, plasticizers, ultraviolet light shielding agents, oxidizing agents, antioxidants, antistatic agents, ultraviolet light absorbers, flame retardants , Processing oil, release agent, colorant, pigment/dye, filler and the like. The above-mentioned additives can be used alone or in combination to form the PS, the PS/alumina mixture, and/or the dry PS/alumina mixture of the PS composition, or can be added to the PS or the PS composition The dry PS/alumina mixture is different from the PS composition of the present disclosure. For example, stabilizers or stabilizers may have been used to help protect the polymeric composition from degradation due to exposure to excessively high temperatures and/or excessive ultraviolet light during the formation of the PS. After the PS is recovered, the additive may have been added, for example, during mixing such as granulation. These additives are included in an amount effective to impart the desired properties. The effective amount of the additives and the method of including these additives in the polymeric composition to produce the PS used in the PS composition of the present disclosure are known to those skilled in the art. For example, the amount of the additive present in the PS or PS composition, based on the total weight of the PS composition or the polymeric composition used to manufacture the PS or PS composition of the present disclosure, may be from 0.1 wt. % To 5 wt%, or from 0.1 wt% to 2 wt%, or from 0.1 wt% to 1.0 wt%.

As indicated above, a variety of additional additives can be included in the PS composition. In a specific example, the PS composition of the present disclosure is outside the SRA and the PS (that is, outside of any additives used during the formation of the polystyrene and introduced separately from the polystyrene and the SRA), It further contains additives. In specific examples, for example, it may be necessary to include a foaming nucleating agent (such as a chemical foaming agent as a foaming nucleating agent, zinc oxide, zirconia, silica, talc and the like) and/or an aging modifier (such as Fatty acid esters, fatty acid amides, hydroxy amides and the like). Other additives that can be used include pigments, pigments, fillers, stability control agents, antioxidants, flame retardants, stabilizers or auxiliary stabilizers (such as sulfides, phosphites, phosphonites, light stabilizers and other Functional stabilizers), fragrances, odor masking agents, antistatic agents, lubricants, foaming aids, coloring agents, deterioration inhibitors and the like. Such additives are well-known to those skilled in the art. In a specific example, the PS composition of the present disclosure includes additives selected from the group consisting of antioxidants, flame retardants, infrared (IR) reducing agents, foaming nucleating agents, and combinations thereof (in any of the PS Additives in and any other than SRA). In a specific example, the PS composition of the present disclosure includes the antioxidant IRGANOX® 1010 (tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid) pentaerythritol ester). As indicated above, in specific examples, one or more additional additives such as, but not limited to, strengthening agents (such as PPO, poly-αmethylstyrene, etc.) are used to improve the mechanical properties of the foam. In specific examples, additives in the form of master batches can also be used. The "master batch" used here is the concentrated blend of the additive.

The PS composition of the present disclosure can further include a foaming agent. In specific examples, any chemical or physical foaming agent can be used. Chemical blowing agents generally decompose when the polymer is melted. For example, a mixture of sodium bicarbonate and citric acid is commonly used to nucleate fine vesicles. Chemical blowing agents generally decompose between about 100°C and about 140°C to produce at least one gas (such as carbon dioxide) and water. In addition, solid particles can potentially serve as nucleation sites. Once the nucleated foam reaches a critical size, it continues to grow due to gas diffusion inside the vesicle until the foam stabilizes to reach the final stage. Suitable chemical blowing agents are known to those skilled in the art. In a specific example, the foaming agent can be a physical foaming agent. Physical blowing agents can be further classified into two categories, including gases and volatile liquids. Gaseous physical blowing agents can include but are not limited to carbon dioxide (CO ₂ ), nitrogen (N ₂ ), argon (Ar), air, helium (He), hydrogen (H ₂ ), xenon (Xe), sulfur hexafluoride (SF ₆ ), nitrogen oxide (N ₂ O), ammonia (NH ₃ ), silicon tetrafluoride (SiF ₄ ), nitrogen tetrafluoride (N ₂ F ₄ ), boron tetrafluoride (BF ₄ ), trichloro Boron (BCl ₃ ) or a combination thereof. Therefore, in a specific example, the blowing agent can be carbon dioxide (CO ₂ ). Volatile liquid physical blowing agents can include, but are not limited to, liquids such as water, and aliphatic or linear hydrocarbons.

In a specific example, a single blowing agent or its kind (for example, HFC, HFO, multiple HFCs, multiple HFOs) is used. In a specific example, multiple blowing agents are used (for example, one or more HFO and/or one or more HFC, optionally combined with one or more additional blowing agents). In a specific example, the blowing agent is selected from the group consisting of hydrofluorocarbons (HFC), hydrofluoroolefins (HFO), and combinations thereof. In a specific example, the blowing agent or the one or more additional blowing agents further include one or more components selected from the group consisting of hydrocarbons, carbon dioxide, nitrogen, and combinations thereof. By way of example, in a specific example, the blowing agent includes one or more HFO, optionally combined with one or more additional blowing agents selected from the group consisting of hydrocarbons, carbon dioxide, nitrogen, HFC, and combinations thereof. By way of alternative examples, in specific examples, the blowing agent includes one or more HFCs, optionally combined with one or more additional blowing agents selected from the group consisting of hydrocarbons, carbon dioxide, nitrogen, HFO, and combinations thereof.

In a specific example, using the dry PS/alumina mixture of the present disclosure in the PS composition will increase the solubility of the blowing agent in the PS composition or the foamable mixture, so that the solubility thereof is higher than The solubility of the blowing agent in other similar PS compositions or foamable mixtures manufactured without the dry PS/alumina mixture (that is, PS is present in approximately the same amount but no alumina is present), At least 5, 10, 15, or 20% higher.

The disclosed PS composition can have a wet density of less than or equal to about 0.09 g/mL (5.6 pounds per cubic foot ("pcf")) measured by ASTM C578. In a specific example, the disclosed PS composition can have a range from about 0.03 to about 0.09 g/mL (from about 1.9 to about 5.6 pcf), from about 0.03 to about 0.085 g/mL (from about 1.9 to about 5.5 pcf). ), from about 0.03 to about 0.08 g/mL (from about 1.9 to about 5.0 pcf) wet density.

Also disclosed here is a low-density polystyrene (PS) foam manufactured by extruding the PS composition of the present disclosure. In a specific example, the low-density polystyrene (PS) foam manufactured by extruding the PS composition of the present disclosure does not contain (for example, not manufactured with it) the dry PS/alumina than by extrusion Other similar low-density PS foams produced by PS compositions of mixed materials (that is, PS is present in approximately the same amount, but no alumina), contain higher foaming agent concentration. For example, in a specific example, the solubility of the foaming agent in the PS composition used to make the foam and/or in the low-density PS foam manufactured by extruding the PS composition of the present disclosure The foaming agent concentration is higher than or equal to about 6.5, 7, 7.5, or 8 weight percent.

In a specific example, the low-density PS foam does not contain (e.g. not made with it) the dry PS/alumina mixture (that is, the PS is present in approximately the same amount, but there is no oxidation. Other similar low-density foams produced by the PS composition of aluminum) exhibit at least one at least equivalent or at least one superior insulating property. The at least one superior insulating property can include the R value determined by ASTM C518. In a specific example, the low-density PS foam exhibits at least one mechanical property, which is at least equivalent to not containing (for example, not manufactured with) the dry PS/alumina mixture (that is, the PS is equal to about The mechanical properties of other similar low-density foams produced by the PS composition of the presence of aluminum oxide. In a specific example, the at least one mechanical property can be compressive strength (measured by ASTM D3574-C). In a specific example, the low-density polystyrene (PS) foam produced by extruding the PS composition containing the blowing agent (which contains one or more hydrofluoroolefins) of the present disclosure exhibits at least one insulating property, It is at least equal to the dry PS/alumina mixture (that is, PS is present in approximately the same amount, but no alumina is present) and contains one or more selected from hydrofluorocarbons without (for example, not manufactured with) the dry PS/alumina mixture through extrusion Other similar low-density foams manufactured by PS composition of foaming agent in the group consisting of HFC.

In a specific example, a PS composition comprising the dry PS/alumina mixture described herein and a foaming agent comprising one or more hydrofluorocarbons (HFC) or one or more hydrofluoroolefins (HFO) The low-density PS foam produced is compared to the others produced by extruding a PS composition that does not contain the dry PS/alumina mixture (that is, the PS is present in approximately the same amount, but there is no alumina). Similar low-density PS foams contain a higher concentration of blowing agent. This low-density PS foam can be manufactured from a PS composition further containing an additional foaming agent. For example, the additional blowing agent can be selected from the group consisting of hydrocarbons, CO ₂ , N ₂ , and combinations thereof.

Without wishing to be bound by theory, the PS/alumina mixture and/or any optional SRA additives can provide permeation barriers in the resulting polystyrene foam of the present disclosure, thereby reducing the penetration of the blowing agent. The penetration rate of the vesicle wall of the PS foam. The (e.g., low-density) polystyrene foam of the present disclosure may therefore exhibit increased foaming agent retention after the foam is formed (e.g., after 15, 30, or 60 days). In a specific example, the low-density polystyrene foam of the present disclosure exhibits foaming agent retention as measured by GC headspace technology, and its ratio is in the absence of the PS/alumina mixture and/or the random Other similar polystyrene foam manufactured under SRA additive (that is, PS is present in approximately the same amount, but no alumina and/or the optional SRA additive is present), at least 0, 5, 10, 15 Or 20%.

The disclosed low-density polystyrene foam can have any desired thickness to suit the desired application. For example, in a specific example, the disclosed polystyrene foam can be in the shape of a sheet or strip, with a thickness ranging from about 1/32 inch to about 2.0 inch. However, thinner or thicker foams can also be included within the scope of the disclosed subject matter. The low-density polystyrene foam can have any required density such as but not limited to a wet density of less than or equal to about 0.09 g/mL (5.6 pounds per cubic foot ("pcf")) as measured by ASTM C578 . In a specific example, the low-density polystyrene foam can have a range of from about 0.02 to about 0.09 g/mL, from about 0.03 to about 0.08 g/mL, from about 0.04 to about 0.08 g/mL, or from about 0.04 g/mL. To a wet density in the range of about 0.06 g/mL.

In a specific example, the disclosed polystyrene foam can have an average vesicle size of at least about 50 microns. In a specific example, the disclosed foam can have an average vesicle size of up to about 1000 microns. The average vesicle size can be measured according to ASTM D3576-98 (Procedure A).

The disclosed polystyrene foam can take any of a variety of configurations such as, but not limited to, sheets, slats, slabs, blocks, plates, rods, beads, and molded shapes.

The method of making the PS foam according to the present disclosure includes forming the dry PS/alumina mixture; blending the dry PS/alumina mixture, a blowing agent, and optionally one or more additional additives to Forming a foamable mixture; and manufacturing the PS foam by extruding the foamable mixture through a die and into a low pressure zone. According to the present disclosure, the PS/alumina mixture must be completely dry (that is, have a water content of less than or equal to about 0.05 wt% water measured by a coulometer) in order to form before extrusion foaming The dry PS/alumina mixture. According to the present disclosure, moisture absorption during foam extrusion is minimized. Forming the dry PS/alumina mixture can include: combining the PS with the alumina additive to form a PS/alumina mixture, and if necessary, removing moisture from the PS/alumina mixture to form the dry The PS/alumina mixture, wherein the dry PS/alumina mixture has a water content of less than or equal to about 0.05 weight percent (wt%) measured by a coulometer. In a specific example, the combination of the PS and the alumina additive produces the dry PS/alumina mixture, that is, the PS and the alumina additive have sufficient dryness before the combination so that they are combined (without further shifting). Water removal) to produce a PS/alumina mixture with a required water content (that is, less than or equal to about 0.05 weight percent (wt%) as measured by a coulometer), so that the PS/alumina mixture is Treated as a dry PS/alumina mixture.

To form the PS/alumina mixture, the PS and the alumina additive can be combined in any suitable manner known to those skilled in the art. For example, in a specific example, the PS and alumina additives are combined by extrusion to provide the PS/alumina mixture. The alumina additive and/or the PS can optionally be dried before combining the alumina additive with the PS. For example, in a specific example, the alumina additive can be dried by heating the alumina additive to a high temperature (for example, higher than or equal to about 120°C, 200°C, or 250°C) and/or maintaining the temperature Under this high temperature for a period of time (for example, longer than or equal to about 2, 3, or 4 hours), it is sufficient to reduce the water content of the alumina additive to, for example, less than or equal to about 0.05, measured by a coulometer, 0.03, or 0 weight percent (wt%) of water content.

By any means known to those skilled in the art and with the help of the present disclosure, moisture can be removed from the PS/alumina mixture to form the dry PS/alumina mixture, which is suitable for reducing the PS/oxidation The water content of the aluminum mixture is to provide a dry PS/alumina mixture with a water content of less than or equal to about 0.05 weight percent (wt%) measured by the electricity meter. For example, removing moisture can include heating the PS/alumina mixture to a high temperature (e.g., greater than or equal to about 50, 60, 70, or 80°C), and/or maintaining the temperature at this high temperature for a period of time ( For example, a time longer than or equal to about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 h), which is sufficient to provide the dry PS/alumina mixture.

Using any of the methods known in this technology, the disclosed polystyrene foam can be formed from the dry PS/alumina mixture. For example, in a specific example, the PS foaming system is manufactured by blending the dry PS/alumina mixture, a foaming agent, and optionally one or more additional additives (such as the hair described above) Foaming agent or additive) to form a foamable mixture; and by extruding the foamable mixture through a die and into a low pressure zone to produce a foam.

In specific examples, any of the above-mentioned chemical or physical foaming agents can be used. As generally understood by those skilled in the art, the foaming agent acts by expanding the thermoplastic resin to produce a vesicle-like thermoplastic structure having a substantially lower density than the resin from which the foam is made. Bubbles are formed around the "nucleation site" and are expanded by heat or low pressure or by chemical reactions that emit gas. Nucleation sites are small particles or clusters of small particles that promote the formation of bubbles in the resin. In a specific example, one or more additives can be incorporated into the resin to promote the nucleation of a particular blowing agent and thereby provide a more uniform void distribution. In a specific example, the alumina serves as the foaming nucleating agent of the PS composition of the present disclosure, and no additional nucleating agent is used to form the low-density PS foam of the present disclosure.

The total amount of foaming agent in the PS composition used to prepare the disclosed PS foam structure depends on conditions such as: the temperature and pressure when the foaming agent is dissolved in the polymer, and the foaming used The chemical and thermophysical properties of the agent, the required density and related properties of the resulting foamed article (such as insulation value, weight to strength ratio, compressive strength, etc.). Therefore, in a specific example, the foaming agent can be mixed with the dry PS/alumina mixture in an amount suitable to achieve the desired degree of expansion in the obtained PS foam. For example, in a specific example, based on 100 parts by weight of the PS composition or foamable mixture, the blowing agent can be added in an amount from about 0.5 to about 15 parts by weight to the dry PS/alumina mixture. Material; in specific examples, from about 2 to 10 parts by weight; and in specific examples, from about 3 to 9 parts by weight.

In a specific example, a continuous extrusion method can be used to construct the disclosed polystyrene foam. In this method, the dry PS/alumina mixture and any additional additives are blended together and added to the extruder. In a specific example, the one or more additional additives can be added in the form of a master batch. Any common type of extruder such as single screw type, twin screw type, and/or tandem type extruder can be used. In the extruder, the dry PA/alumina mixture and any additional additives are melted and mixed to provide a PS/alumina blend. The blowing agent is added to the molten PS/alumina blend through one or more injection ports of the extruder. As indicated above, any additional additives to be used can be added to the melted PS/alumina blend in the extruder and/or with the PS resin pellets and/or the dried PS/ Add alumina mixture together. The extruder pushes the entire melt mixture (melted PS/alumina blend, blowing agent, and any additional additives) through the die at the end of the extruder and into the inside of the extruder. In the temperature and pressure zone where the temperature and pressure are relatively reduced. Any of a variety of molds can be used, including but not limited to strip, ring, flat, co-extruded, and micro-laminated molds. In a specific example, the low temperature and pressure zone can be under the surrounding atmosphere. As the polymer leaves the mold, the pressure drop caused by the gas-filled polymer causes the thermodynamic instability. The nucleating agent (e.g. alumina) generates a lot of foam and grows due to the diffusion of volatilized gas into the growing vesicles. The foam continues to expand until the vesicle grows up and is stable. When the polymer substance is cooled, the surface of the foam solidifies due to the decrease in temperature, so that the foaming agent is trapped in the vesicle. As a result, an extruded polystyrene foam is formed.

Alternatively, in a specific example, a batch method can be used to construct the disclosed polystyrene foam. In these specific examples, the polystyrene blend (ie, the dry PS/alumina mixture and any additional additives required) is added to a container such as a pressure chamber. The container is heated to a specific temperature or temperature range sufficient to plasticize the polystyrene resin. The blowing agent is then added to the container to reach a specific pressure or pressure range, and the blowing agent is allowed to penetrate the polystyrene resin for a period of time. The pressure is quickly released, so that the resin expands into a PS foam.

The disclosed subject matter also includes additional foaming methods, including but not limited to solid foaming, integral skin foaming, microvesicle foaming, autoclave foaming, and semi-continuous foaming methods. This method is well-known to those skilled in foaming technology. In a specific example, the optional additional additives (such as SRA, flame retardants, IR reducers/inhibitors, antioxidants, and/or others) can be added to other common polystyrene blends in the form of master batches.

As enumerated herein, the disclosed method can be used to form a polystyrene foam using a physical blowing agent (for example, one or more HFO, one or more HFC, carbon dioxide, and/or others). Depending on the materials and methods used, the resulting foam objects can be beads, sheets, plates, slats, rods, tubes, contour members, or the like. The disclosed polystyrene foam can be used as a prototype, cut into other shapes, further shaped or thermoformed by applying heat and/or pressure, or mechanically processed or formed into objects of desired size and shape, such as Generally known to those skilled in packaging technology.

The disclosed polystyrene foam can be used for any of a variety of purposes. For example, in specific examples, the disclosed polystyrene foam can be used for insulation and/or as a protective or flexible packaging for various containers and packaging systems. Therefore, in specific examples, the disclosed polystyrene foam can be thermoformed into containers, such as but not limited to plates, bowls, and/or dishes, for flexible and rigid packaging, and for a variety of protective properties. Packaging applications, used for bulk packaging, and/or can be molded into sheets, slats, boards, or contoured objects for flexible, protective, rigid, and/or insulating applications.

As indicated above, the PS composition disclosed herein and the method for producing PS foam therefrom can make the foaming agent have greater solubility in PS during extrusion and/or in the resulting PS foam There is a higher concentration of blowing agent. The combination of a higher blowing agent concentration in the resulting polystyrene foam can provide enhanced insulation properties to the polystyrene.

In addition, it has been found that when a dry PS/alumina mixture is used to form the PS composition according to the present disclosure, the PS composition can be developed in the presence of a physical blowing agent (such as carbon dioxide and/or HFO). bubble. In a specific example, the non-flammability and/or low GWP of the blowing agent makes it have improved safety and/or environmental friendliness compared to common combustible or high GWP hydrocarbons. The use of physical foaming agents can also help reduce the curing time of the foam, which can save time, effort and money. [Example]

After the specific examples have been described in general, the following examples are given as specific examples of the present disclosure and verify its implementation and advantages. It is understood that these examples are given by way of explanation and are in no way intended to limit the scope of this specification or the patent application. Example 1

In this example, three PS foams were manufactured and studied, including the first comparative foam C1 manufactured by using a PS composition containing standard polystyrene PS533 and no alumina additives, and using a PS containing wet PS/ The second comparative foam C2 manufactured by the PS composition of the alumina mixture (which contains the PS PS533 and 1 wt% alumina additive and water) and the dry PS/alumina mixture (which contains the PS PS533 and 1 wt% alumina additive are dried to be substantially free of moisture, for example, by drying in a nitrogen scavenging oven at 250° C. for 2 hours). The PS foam I1 of the present invention is manufactured. The alumina additive used in this example is Sasol CATAPAL® Cl, and its related properties are provided in Table 1 above, including a particle size d _{50 of} 60 microns.

In particular, the first comparative foam C1 is a standard foam made from polystyrene PS533 dry blended with 0.5% of the talc masterbatch used for foam extrusion. PS533 has an MFR of 4.5g/10min and can be obtained from Total Petrochemicals and Refining USA, Inc. A 1.25" single-screw extruder was used to produce a large PS/alumina mixture containing PS533 and 1 wt% of dry alumina additives. The PS/alumina mixture was dried and divided into two parts. Drying was included at 250°C The dried PS/alumina mixture was dried for about 2 hours in a nitrogen removal furnace. The first half of the dried PS/alumina mixture was directly used for foam extrusion to form the foam I1 of the present invention. Deionized water in an amount of 0.75 wt% Add to the other half of the PS/alumina mixture, which is then left to stand overnight to allow the foam to fully absorb moisture before the foam is extruded to form the second comparative foam C2.

The foam extrusion was evaluated using the Applications Laboratory Davis Standard foam line. As mentioned above, the comparative foam C1 formed by dry blending PS533 with 0.5% talc masterbatch as a nucleating agent for the foam extrusion. The alumina additive is used as a foaming nucleating agent in the PS/alumina mixture used to form the second comparative foam C2 and the foam I1 of the present invention. Therefore, no additional nucleating agent is It is added to the PS composition used to form the second comparative foam C2 and the foam I1 of the present invention.

Using different amounts of HFC 134a (also known as R134a) as a blowing agent, the foam extrusion of the PS composition was evaluated. The PS composition was foamed in a tandem foam extrusion line containing a 0.75" primary extruder and a 1.5" secondary extruder. In particular, place the sample in the feed hopper of the main extruder. The blowing agent HFC 134a was fed into the main extruder through the MaxPro liquid pump. The homogenized melt is fed into the secondary extruder through a Nordson Xaloy melt pump. Adjust the temperature of the secondary extruder to maintain a constant die head pressure of 1100-1200 psi under different HFC 134a blowing agent content. As the melt leaves the mold, a low-density foam is produced. Use a 5 mm rod-shaped die to extrude all samples. A gear pump was used to control the extrusion flux between 6.5 and 7 lbs/hr. The maximum solubility of HFC 134a is defined as the foaming agent content when premature foaming becomes visible (for example, and foam density increases). The first comparative example C1

The PS foam C1 made of standard PS533 polystyrene produces a foam with a consistent vesicle structure under the condition of less than 7% of the blowing agent HFC 134a. However, at higher HFC 134a foaming agent content, premature foaming becomes obvious, which is most likely to result in a non-uniform foam vesicle structure before the breaker plate of the die head is approached. Bulb defect. Under the foaming conditions established on the line of the small laboratory, the maximum HFC 134a foaming agent solubility for PS compositions containing standard PS533 and no alumina additives was determined to be about 7 wt% of HFC 134a. Figure 1A provides an image of the first comparative foam sample C1 of this example containing 7 wt% of the blowing agent HFC 134a, and Figure 1B provides the first example of this example containing 8 wt% of the blowing agent HFC 134a Image of comparative foam sample C1. The second comparative example

Under standard conditions, the foam extrusion of the wet PS533/alumina mixture was investigated. Similar to what was seen for the first comparative foam C1, the second comparative foam C2 having a uniform vesicle structure was produced when the HFC 134a foaming agent concentration was lower than 7 wt%. Due to the abundance of water, double-vesicle foams are produced in the same way. However, at a HFC 134a concentration of 7wt% or higher, premature foaming obviously impairs the quality of the second comparative C2 foam obtained. Moisture is therefore not an effective plasticizer for PS crystals, and compared to the first comparative C1 foam that does not contain alumina, it does not provide benefits at high HFC 134a content. Overall, the maximum solubility of HFC 134a in the wet PS/alumina mixture used to make the second comparative foam C2 is up to 7%, which is the same as that seen for the first comparative foam C1 similar. Figure 2A provides an image of the second comparative foam sample C2 of this example containing 6 wt% of the blowing agent HFC 134a, and Figure 2B provides the second example of this example containing 7 wt% of the blowing agent HFC 134a Image of comparative foam sample C2. Examples of the invention

Under the standard conditions, the foaming extrusion of the dried PS533/alumina mixture was investigated to produce the foam I1 of the present invention. Similar to the standard PS533 used to manufacture the first comparative foam C1 and the wet PS/alumina mixture used to manufacture the second comparative foam C2, when the HFC 134a foaming agent concentration is lower than 7 At wt%, the dry PS/alumina mixture is used to produce extremely good foams (for example, foams with a uniform vesicle structure). The successful I1 foam was also manufactured at a concentration of HFC 134a higher than 8.5 wt%.

Figure 3A provides an image of the foam sample I1 of the present example containing 6 wt% of the blowing agent HFC 134a, and Figure 3B provides the present invention containing 7 wt% of the blowing agent HFC 134a of this example The image of the foam sample I1, and FIG. 3C provides an image of the foam sample I1 of the present invention containing 8.5 wt% of the foaming agent HFC 134a of this example. As seen in Figures 3A-3C, an expanded foaming system with a consistent vesicle structure is obtained from the dry PS533/alumina mixture (even under 9 wt% of the blowing agent HFC 134a). The second comparative foam C2 obtained from the wet PS533/alumina mixture at 7.5% of 134a showed improvement. It is also indicated that at a higher concentration of HFC 134a, a relatively low foam density (such as the foam density of the present invention I1) can be produced from the dry PS533/alumina mixture. Based on the established protocol, the maximum solubility of HFC 134a in the dry PS533/alumina mixture appears to be about 9 wt%. Figure 4 shows a side-by-side comparison of the second comparative foam sample C2 under 7wt% and 7.5wt% HFC 134a blowing agent and the foam sample I1 of the present invention under 9wt% HFC 134a blowing agent. Figure 5 shows the wet density (g) as a function of the concentration (wt%) of the blowing agent HFC 134a for the first comparative foam C1, the second comparative foam C2 and the foam I1 of the present invention /cc) of the drawing. The wet density is measured by ASTM C578. Overall, the use of the pre-dried PS533/1 wt% alumina mixture in the PS composition significantly improves the solubility of the HFC 134a blowing agent. It is expected that the porosity of the dried alumina additive will promote the absorption of the HFC 134a blowing agent in the PS mixture. Interesting finding: Although only 1% alumina is used in this example, the pre-dried PS/alumina mixture can be processed at a maximum HFC 134a blowing agent concentration higher than 9 wt%. This is equivalent to the fact that the PS composition containing the dry PS/alumina mixture used in the production of the foam I1 of the present invention contains PS533 and no more than the PS composition used in the production of the first comparative foam C1 In the standard PS composition of alumina additives, the solubility of the blowing agent is increased by more than 20%. The additional alumina can be used to further improve the solubility of the HFC 134a blowing agent in the PS composition used in the production of the PS foam, and thus to further improve the concentration of the blowing agent in the resulting PS foam.

Although different specific examples have been shown and described, their improvement can be accomplished by those skilled in the art without departing from the spirit and teachings of the present disclosure. The specific examples described here are merely illustrative and are not intended to be limiting. Many changes and improvements on the subject matter disclosed herein are possible and within the scope of this disclosure. When a numerical range or limit is clearly stated, these definite ranges or limits should be understood to include cumulative ranges or limits of similar magnitude (for example, from about 1 to about 10) that fall within the clearly stated range or limit. Including 2, 3, 4, etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). For example, whenever a _{numerical range with a lower limit RL} and an upper limit _RU is revealed, any number falling within the range is specifically revealed. In particular, the following numbers within this range are specifically revealed: R=R _L +k*(R _U -R _L ), where k is a variable with an increase rate of 1% in the range of 1% to 100%, also That is, k is 1%, 2%, 3%, 4%, 5%,...,50%, 51%, 52%,...,95%, 96%, 97%, 98%, 99%, or 100%. Furthermore, any number range defined by the two R numbers defined above is also specifically disclosed. In relation to any element in the scope of the patent application, the use of the term "arbitrarily" is intended to indicate whether the element is required or not. The second option is to be within the scope of the patent application. The use of broader terms such as including, including, having, etc. should be understood to provide support for narrower terms such as consisting of, basically consisting of, and substantially consisting of.

Therefore, the scope of protection is not limited to the descriptions listed above, but only limited to the scope of the following patent application, which includes all equivalents of the subject matter of the scope of the patent application. The scope of each patent application is incorporated into the specification as a specific example of the present disclosure. Therefore, the scope of the patent application is further explained and appended to the specific examples of the present disclosure. The discussion of the cited materials is not an admission that it is the prior art of the present disclosure. In particular, any cited materials may have a public announcement date after the priority date of this application. The disclosures of all patents, patent applications, and public announcements cited herein are incorporated herein by reference to the extent that they provide examples, procedures, or other details supplements to those listed here in. Extra note

The specific examples disclosed above are only illustrative, because the present disclosure can be improved and implemented in a different but equivalent manner to those skilled in the benefits taught herein. Furthermore, there is no intention to limit the details of the structure or design shown here beyond those described in the scope of the following patent applications. Therefore, it is obvious that the specific illustrative examples disclosed above can be modified or improved, and all such variations are considered to be within the scope and spirit of the present disclosure. Alternative specific examples obtained by combining, integrating, and/or omitting the features of this specific example are also within the scope of the present disclosure. Although the composition and method are described in broad terms that "have", "include", "contain", or "include" different ingredients or steps, the composition and method can also be "basically composed" or "from" such Different ingredients or steps "constitute". In relation to any element in the scope of the patent application, the use of the term "arbitrarily" means that the element is necessary or not, and the two options are within the scope of the patent application.

The figures and ranges disclosed above may be slightly changed. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number within the range or any included range is specifically disclosed. In particular, each value disclosed here (from "from about a to about b" or equivalently "from about a to b" or equivalently "from about ab") should be understood to be listed in the broader Every number and range included in the numerical range. In addition, the terms in the scope of the patent application have their clear and ordinary meanings unless they are clearly defined otherwise by the patentee. Furthermore, the indefinite article "a" used in the scope of the patent application is defined here to indicate that it introduces one or more of the elements. If there is a contradiction between the use of words or terms in this specification and one or more patents or other documents, the definition consistent with this specification shall be adopted.

The specific examples disclosed here include:

Specific Example A: A polystyrene (PS) composition for making extruded foams, the PS composition comprising: a dry PS/alumina mixture containing PS and alumina additives, wherein the dry PS The /alumina mixture has a water content of less than or equal to about 0.05 weight percent (wt%) measured by a coulometer; and a foaming agent.

Specific Example B: A low-density polystyrene (PS) foam manufactured by extruding the PS composition of Specific Example A, wherein the low-density PS foam is higher than that without the dry PS/ Other similar low-density PS foams made from the PS composition of the alumina mixture have a higher foaming agent concentration.

Specific Example C: A low-density polystyrene (PS) foam manufactured by extruding the PS composition of Specific Example A, wherein the low-density PS foam is relatively extruded without the dry PS Other similar low-density PS foams made from the PS composition of the alumina/alumina mixture exhibit at least one superior insulating property.

Specific Example D: A low-density polystyrene (PS) foam manufactured by extruding the PS composition of Specific Example A, wherein the low-density PS foam exhibits at least one mechanical property, which is at least equivalent to through extrusion Other similar low-density PS foams made by PS compositions that do not contain the dry PS/alumina mixture.

Example E: A low-density polystyrene (PS) foam manufactured by extruding the PS composition of Example A, wherein the blowing agent contains one or more hydrofluoroolefins (HFO), and wherein the low-density polystyrene (PS) foam Density PS foam exhibits at least one insulating property, which is at least equivalent to extruding the PS/alumina mixture without the dry and containing one or more selected from the group consisting of hydrofluorocarbons (HFC) Other similar low-density PS foams made from the PS composition of the foaming agent.

Specific Example F: A method of manufacturing low-density polystyrene (PS) foam, the method comprising: forming a polystyrene (PS)/alumina mixture containing PS and alumina additives; from the PS/alumina The mixture removes moisture to form a dry PS/alumina mixture, wherein the dry PS/alumina mixture has less than or equal to about 0.05 weight percent (wt%) water measured by the electricity meter Content; blend the dry PS/alumina mixture, blowing agent, and any one or more additional additives to form a foamable mixture; and by extruding the foamable mixture through a mold and into Low pressure zone to produce foam.

Specific Example G: A low-density polystyrene (PS) foam manufactured by the method of Specific Example F.

Specific Example H: The low-density PS foam of Specific Example G, wherein the low-density PS foam is similar to other foamable mixtures manufactured by extruding a foamable mixture that does not contain the dry PS/alumina mixture The low-density PS foam contains a higher blowing agent concentration and/or exhibits at least one superior insulation or mechanical property.

Specific Example I: A dry polystyrene (PS)/alumina mixture for making extruded foams, the dry PS/alumina mixture contains an extruded mixture of PS and alumina additives, wherein the The extruded mixture has been dried to provide the dry PS/alumina mixture so that the dry PS/alumina mixture has less than or equal to about 0.05 weight percent (wt%) water as measured by the electricity meter Content, wherein the dry PS/alumina mixture contains from about 0.01 to about 20.0 weight percent (wt%) of alumina additive.

J: A low-density polystyrene (PS) foam manufactured by extruding a PS composition, which contains: a dry PS/alumina mixture containing PS and alumina additives, wherein the dry PS/oxidation The aluminum compound has a water content of less than or equal to about 0.05 weight percent (wt%) measured by a coulometer; and a foaming agent, wherein the PS composition contains more than or less than about 7 weight percent of the Foaming agent.

Specific examples A, B, C, D, E, F, G, H, I, and J may have one or more of the following additional elements: Element 1: wherein the dry PS/alumina mixture contains from about 0.01 to Approximately 20.0 weight percent (wt%) alumina additive. Element 2: The alumina additive contains Sasol CATAPAL® Cl. Element 3: Wherein the PS contains polystyrene crystals, high impact polystyrene (HIPS), PS copolymer, or a combination thereof. Element 4: The PS copolymer contains metal monomers, glycidyl methacrylate, 2-hydroxyethyl methacrylate, acrylonitrile, or a combination thereof. Element 5: The PS has a melt flow rate (MFR) from 0.2 to 30 grams (g)/10 minutes (min) as measured by ASTM D-1238. Element 6: further containing additives, which include glyceryl monostearate (GMS), glyceryl tristearate (GTS), mineral oil (MO), epoxidized soybean oil (ESO), epoxidized polybutadiene, Or a combination. Element 7: Containing from about 0.01 to 10.0 weight percent (wt%) of the additive, the weight percent being based on the total amount of the polystyrene and the additive in the PS composition. Element 8: further comprising additives selected from the group consisting of oxidants, flame retardants, and combinations thereof. Element 9: wherein the solubility of the blowing agent in the PS composition is higher than or equal to about 7 weight percent. Element 10: The blowing agent is selected from the group consisting of hydrofluorocarbon (HFC), hydrofluoroolefin (HFO), carbon dioxide (CO ₂ ), and combinations thereof. Element 11: wherein the dry polystyrene (PS)/alumina mixture contains from about 0.01 to about 20.0 weight percent (wt%) of alumina additive. Element 12: The solubility of the blowing agent in the foamable mixture is at least 5 higher than that of other similar foamable mixtures manufactured without the dry PS/alumina mixture. 10, 15, or 20%. Element 13: The one or more additional additives are selected from glyceryl monostearate (GMS), glyceryl tristearate (GTS), mineral oil (MO), epoxidized soybean oil (ESO), epoxidized poly The group consisting of butadiene, flame retardant, antioxidant, and combinations thereof. Element 14: Wherein the blowing agent contains one or more hydrofluoroolefins, and where the low-density PS foam exhibits at least one insulating property, which is at least equivalent to extruding without the dry PS/alumina It is mixed with other similar low-density PS foams produced by a foamable mixture of one or more foaming agents selected from the group consisting of hydrofluorocarbons (HFC). Element 15: wherein the blowing agent contains one or more hydrofluorocarbons (HFC) or one or more hydrofluoroolefins (HFO), and wherein the low-density PS foam is relatively extruded without the dry Other similar low-density PS foams made from the foamable mixture of PS/alumina mixtures contain a higher concentration of the foaming agent. Element 16: further includes an additional blowing agent selected from the group consisting of hydrocarbons, CO ₂ , and combinations thereof.

Although the preferred embodiments of the present invention have been shown and described, their improved versions can be completed by those skilled in the art without departing from the teachings of the present disclosure. The specific examples described here are merely illustrative and are not intended to be limiting. Many variations and improvements of the present invention disclosed herein are possible and are within the scope of the present invention.

After fully understanding the above disclosure, those skilled in this technology will understand many other improved, equivalent, and alternative types. The scope of the following patent applications, where applicable, is intended to be interpreted as including all such improvements, equivalents, and alternatives. Therefore, the scope of protection is not limited to the descriptions listed above, but is only limited to the scope of the following patent applications, which includes all equivalents of the subject matter of the scope of the patent applications. The scope of each patent application is incorporated into the specification as a specific example of the present invention. Therefore, the scope of these patent applications is a further explanation and addition to the detailed description of the present invention. All patents, patent applications, and public announcements cited herein are incorporated herein by reference.

In order to fully understand the present disclosure and its advantages, now refer to the following brief description together with the accompanying drawings and detailed description, in which similar reference numerals represent similar components.

[Figure 1A] Provides an image of the first comparative foam sample C1 of Example 1 containing 7 wt% of the blowing agent HFC 134a;

[Figure 1B] Provides an image of the first comparative foam sample C1 of Example 1 containing 8 wt% of the blowing agent HFC 134a;

[Figure 2A] Provides an image of the second comparative foam sample C2 of Example 1 containing 6 wt% of the blowing agent HFC 134a;

[Figure 2B] Provides an image of the second comparative foam sample C2 of Example 1 containing 7 wt% of the blowing agent HFC 134a;

[Figure 3A] Provides an image of the foam sample I1 of the present invention of Example 1 containing 6 wt% of the blowing agent HFC 134a;

[Figure 3B] Provides an image of the foam sample I1 of the present invention of Example 1 containing 7 wt% of the blowing agent HFC 134a;

[Figure 3C] Provides an image of the foam sample I1 of the present invention of Example 1 containing 8.5 wt% of the blowing agent HFC 134a;

[Figure 4] shows the side by side of the second comparative foam sample C2 of Example 1 containing 7 wt% and 7.5 wt% of HFC 134a and the foam sample I1 of the present invention of Example 1 containing 9 wt% of HFC 134a Compare

[Figure 5] is a graph of wet density (g/cc) as a function of the concentration (wt%) of the blowing agent HFC 134a used in the composition of Example 1.

Claims (21)

A polystyrene (PS) composition for making extruded foams, the PS composition comprising: A dry PS/alumina mixture containing PS and alumina additives, wherein the dry PS/alumina mixture has a water content of less than or equal to about 0.05 weight percent (wt%) measured by a coulometer ;as well as Foaming agent. The PS composition of claim 1, wherein the dry PS/alumina mixture contains about 0.01 to about 20.0 weight percent (wt%) of the alumina additive. Such as the PS composition of claim 1, wherein the alumina additive contains Sasol CATAPAL® Cl. The PS composition of claim 1, wherein the PS comprises polystyrene crystal, high-impact polystyrene (HIPS), PS copolymer, or a combination thereof. The PS composition of claim 4, wherein the PS copolymer contains a metal monomer, glycidyl methacrylate, 2-hydroxyethyl methacrylate, acrylonitrile, or a combination thereof. The PS composition of claim 1, wherein the PS has a melt flow rate (MFR) in the range from 0.2 to 30 grams (g)/10 minutes (min) as measured by ASTM D-1238. Such as the PS composition of claim 1, which further comprises an additive comprising glyceryl monostearate (GMS), glyceryl tristearate (GTS), mineral oil (MO), and epoxidized soybean oil (ESO) , Epoxidized polybutadiene, or a combination thereof. Such as the PS composition of claim 7, which contains from about 0.01 to 10.0 weight percent (wt%) of the additive, and the weight percent is based on the total amount of the polystyrene and the additive in the PS composition. The PS composition of claim 1, wherein the solubility of the foaming agent in the PS composition is higher than or equal to about 7 weight percent. A low-density polystyrene (PS) foam manufactured by extruding the PS composition of claim 1, wherein the low-density PS foam does not contain the dry PS/alumina mixture than through extrusion Other similar low-density PS foams made by the PS composition contain higher foaming agent concentration. Such as the low-density PS foam of claim 10, wherein the blowing agent is selected from the group consisting of hydrofluorocarbon (HFC), hydrofluoroolefin (HFO), carbon dioxide (CO ₂ ), and combinations thereof. A method of manufacturing low-density polystyrene (PS) foam, the method comprising: Form a polystyrene (PS)/alumina mixture containing PS and alumina additives; Moisture is removed from the PS/alumina mixture to form a dry PS/alumina mixture, wherein the dry PS/alumina mixture has less than or equal to about 0.05 weight percent as measured by a coulometer (wt%) water content; Blending the dry PS/alumina mixture, blowing agent, and optional one or more additional additives to form a foamable mixture; and The foam is manufactured by extruding the foamable mixture through a die and into a low pressure zone. The method of claim 12, wherein the dry polystyrene (PS)/alumina mixture contains from about 0.01 to about 20.0 weight percent (wt%) of the alumina additive. The method of claim 12, wherein the solubility of the foaming agent in the foamable mixture is higher than that of the foaming agent in other similar foamable mixtures manufactured without the dry PS/alumina mixture The solubility is at least 5, 10, 15 or 20% higher. A low-density polystyrene (PS) foam manufactured by the method of claim 12. The low-density PS foam of claim 15, wherein the low-density PS foam is relatively low-density manufactured by extruding a foamable mixture that does not contain the dry PS/alumina mixture PS foam contains a higher concentration of blowing agent and/or exhibits at least one superior insulation or mechanical property. The low-density PS foam of claim 15, wherein the blowing agent contains one or more hydrofluoroolefins, and wherein the low-density PS foam exhibits at least one insulating property, and the insulating property is at least equal to The dry PS/alumina mixture contains one or more foamable mixtures of selected blowing agents in the group consisting of hydrofluorocarbons (HFC) and other similar low-density PS foams The insulating properties. The low-density PS foam of claim 15, wherein the blowing agent contains one or more hydrofluorocarbons (HFC) or one or more hydrofluoroolefins (HFO), and wherein the foaming agent does not contain the dry Other similar low-density PS foams produced by the foamable mixture of the PS/alumina mixture, which contain a higher concentration of foaming agent. Such as the low-density PS foam of claim 18, which further comprises an additional foaming agent selected from the group consisting of _{hydrocarbons, CO 2, and combinations thereof.} A dry polystyrene (PS)/alumina mixture used to make extruded foams. The dry PS/alumina mixture contains an extruded mixture of PS and alumina additives, wherein the extruded mixture has been Drying to provide the dry PS/alumina mixture so that the dry PS/alumina mixture has a water content of less than or equal to about 0.05 weight percent (wt%) measured by a coulometer, wherein the The dry PS/alumina mixture contains from about 0.01 to about 20.0 weight percent (wt%) alumina additive. A low-density polystyrene (PS) foam manufactured by extruding a PS composition, which contains: A dry PS/alumina mixture containing PS and alumina additives, wherein the dry PS/alumina mixture has a water content of less than or equal to about 0.05 weight percent (wt%) measured by a coulometer ;and A foaming agent, wherein the PS composition contains greater than or equal to about 7 weight percent of the foaming agent.

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